In the poem "Stopping by Woods on a Snowy Evening," is the speaker happy with his lonely state in the woods?

In Robert Frost's beloved poem "Stopping by Woods on a Snowy Evening," the speaker (let's assume he's a man) stops while riding on horseback to look at the snow falling in the woods. He does not speak of his mood until the last stanza. He speaks of the owner of the woods, and his horse, and the falling snow. The last stanza gives us a hint as to why he is stopping. He seems to be weighed down by responsibilities, for he says, "I have promises to keep and miles to go before I sleep." He finds the quiet scene comforting, perhaps a reprieve from the duties of life that are pushing him onward this evening. I wouldn't describe his mood as happy. He takes pleasure in the calm serenity of the "easy wind and downy flake" and the beauty of his surroundings. Nevertheless, there is a nagging sense of responsibility that won't let him completely give himself over to happiness, just like the horse's impatient jangling of his harness bells won't allow the air to remain totally quiet.